What is the greatest threat to the future of humanity?

[AZGrizFan]

Yellowstone megaeruption.
Meteor

Nuclear war would be devastating, but I dont’ think it would wipe out ALL of humanity. Nor would overpopulation or any of the other issues noted.

The "war" itself wouldn't, but a global nuclear fallout would kill off humanity in the ensuing decades.

The atmosphere is contaminated, the water is contaminated, and food sources are contaminated. A spike in cancers, malnutrition, and disease would dwindle us to numbers where healthy/nearby breeding partner are scarce. This wouldn't even take into account the sudden infrastructure, knowledge, and skilled workforce lost in a global nuclear war...the stuff critical for our survival in this scenario (especially knowledge).

We'd essentially be living on a hostile, foreign planet which our bodies had no time to adapt to.

Nope. Much like “climate change”, the large-scale impact of nuclear war is overstated. As I stated, it would be devastating, but it would NOT wipe out all of humanity. All that “stuff” critical for our survival is for survival as WE know it. World might go back to the dark ages, but humanity would survive.

[AZGrizFan]

If I'm rating fears on a scale of 0 to 10, I give pandemics/superbugs a 2/10, nuclear war a 1/10, and AI a 0/10.

I think climate and overpopulation are a concern, but not in the same way most would.

Advanced countries will be able to work around issues of climate even if food and water will no longer be as abundant and cheap as they are today. The problem is going to be the inevitable refugee crisis from developing countries where people are reproducing like rabbits.

If the day comes when there's unprecedented famines in the Middle East, Sub-Saharan Africa, and the poorest parts of Latin America the west will either have to go full Donald Trump and put up physical barriers to keep people out or keep living under the delusion that they can assimilate very large numbers of third-worlders. And of course the western countries will probably roll the dice and open up the doors because their birth rates are so low, which will create all kinds of fiscal and social problems and allow Trumpian populists to win elections.

I honestly think people are going to be around in this world for a very long time. But we might be seeing the world today being about as good as it's ever going to get.

As my boss would say, that’s LOSER talk!